Due to endemic contamination of the environment in areas of South Africa by pesticides used in agriculture and for disease prevention, the neurotoxicity of these substances is of major concern as a health hazard among inhabitants of rural areas. Several classes of pesticides are known to be neurotoxic in adult populations with occupational and environmental exposures to them and some pesticides are well established as endocrine disruptors, affecting sexual maturation during prenatal growth and in children. However, very little is known about the effects of these chemicals on central nervous system (CNS) development in utero and in early childhood. Knowledge concerning the neurodevelopmental effects of these substances is of critical importance because of the fragility of the brain in early development, the known structural and neurochemical effects of pesticides on the brain, and potential neurotoxicity during development secondary to endocrine disruption. Children in South Africa are particularly susceptible to the effects of environmental exposure to pesticides in utero because of maternal exposure to pesticides. This work has important public health implications in South Africa, including documentation of the severity and types of pesticide exposure identified through biological and environmental assessments and the acquisition of new knowledge concerning the neurodevelopmental effects of exposures to these chemicals. Such knowledge will be important for public health policy in South Africa, including development of primary prevention and educational programs designed to reduce exposure and adverse health effects. It was also be applicable to development of public health policy in other parts of the world, including the United States. Longitudinal investigation of the effects of prenatal pesticide exposure on neurodevelopment of children in South Africa is the long-range goal of the work proposed in this application for pilot funding. The procedures described in the proposal will be pursued in order to develop the collaborative mechanisms, pilot methods, and feasibility studies that will facilitate the design and completion of such an investigation. The communities of interest are rural areas in KwaZulu-Natal, where pesticide contamination is widespread. Collaboration between district health personnel, scientists at the University of Cape Town and the University of Natal in South Africa, and investigators at Boston University is key to the project.